Electric lamp/reflector unit employing a ceramic insert

ABSTRACT

The invention provides a new PAR 38 lamp/reflector unit comprising a halogen lamp of suitable power, i.e. 100 watts/120 volts, coated with infrared film to reflect infrared energy produced by the halogen lamp back to the filament, making it more efficient; that meets and preferably exceeds the minimum EPACT efficacy standards, that exhibits a median life of at least about 3000 hours, while giving light output greater than 90% from the original value at about 1750 hours. Unit comprises a double-ended electric lamp ( 10 ) arranged in a reflector body ( 1 ) in a manner that first end portion ( 21 ) is at least partly situated in the neck-shaped portion ( 5 ), cavity ( 13 ) is situated within reflecting portion ( 2 ), the electric light source ( 16 ) is predominantly situated on the optical axis ( 4 ), a ceramic insert ( 42 ), beneath mounting ring ( 40 ) through which the seal of first end portion ( 21 ) is passed, is effective to dissipate heat from first end portion ( 21 ) during operation of the lamp.

The invention relates to an electric lamp/reflector unit comprising areflector body including a reflector portion having a concave reflectingsurface with an optical axis and, integral therewith, a hollowneck-shaped portion about the optical axis, an electric lamp providedwith a gastight light-transmitting lamp vessel which comprises: aquartz-glass wall which encloses a cavity of a predetermined, ingeneral, spherical or elliptic shape with a geometric center, saidquartz-glass wall being at least partly provided with aninfrared-reflecting and visible light-transmitting coating, said cavityaccommodating a substantially linear electric light source, a metal foilwhich is entirely embedded in the quartz-glass wall and connected to theelectric light source, a first end portion and a second end portionwhich are arranged so as to be opposite to each other and which bothcomprise a seal, through which seals a respective current conductor,which is connected to the embedded metal foil, issues from the lampvessel to the exterior.

The invention further relates to an electric lamp for use in an electriclamp/reflector unit.

Such electric lamp/reflector units are used as a source of white lightfor general and decorative lighting applications to show objects intheir true colors.

Such a lamp is well known in the lighting industry and includes, forexample, an electric lamp/reflector unit of the type mentioned in EP-A 0397 422. In said document a description is given of a so-calleddouble-ended halogen lamp provided with an infrared-reflectinginterference filter, which lamp is arranged in a reflector body of thePAR 38 type, where the abbreviation PAR stands for Parabolic AluminumReflector, and the number “38” indicates a diameter of the reflectorbody at the location of the light emission window, the diameter beingobtained by multiplying said number with an eighth of an inch, 1 inchbeing 25.4 mm, so that the diameter of the emission window of a PAR 38reflector is 38×⅛ inch or approximately 121 mm.

As part of a worldwide movement towards more energy efficient lighting,in more recent years government legislation in the United States(commonly referred to as the national Energy Policy Act “EPACT”) hasmandated lamp efficacy values for many types of commonly used lampsincluding PAR lamps. Only products meeting these efficacy levels may besold in the United States. These minimum efficacy values for PAR-38incandescent lamps are for example, lamps of 51-66 W must achieve 11lumens per Watt (LPW), lamps of 67-85 W must achieve 12.5 LPW, lamps of86-115 W must achieve 14 LPW, and lamps in the range of 116-155 W mustachieve 14.5 LPW. It is possible to design a lamp for a conventionalPAR-38 lamp that will meet EPACT standards. However, designing such alamp heretofore has resulted in a greatly reduced lamp life. This isattributed to the fact that while the IR-coated burner has a higherbrightness and a higher luminous efficacy, the seal of the lamp vesselassumes a comparatively high temperature during operation which hightemperature results in shortened lamp life. Another cause of the shortlife of halogen lamps is molybdenum corrosion. For these and otherreasons, as the press temperature increases, the possibility of the lampfailing early increases as well.

U.S. Pat. No. 5,646,473, titled “ELECTRIC REFLECTOR LAMP”, issued Jul.8, 1997 and assigned to the same assignee as in the present application,relates to an electric reflector lamp in which the lamp vessel containsa light source that may be, for example, an incandescent body in a gascomprising halogen and may be covered with an IR-reflecting interferencefilter. The lamp also comprises a ceramic body which surrounds the sealto lower the temperature during operation. Such lamps are disclosed tobe of relatively low power, for example, 75 W for a lamp without anIR-reflecting interference filter, and 68 W for a lamp without anIR-reflecting interference filter, when operated at mains voltage. Thelamp life and efficacy of such lamps are not disclosed.

U.S. Pat. No. 5,281,889 issued Jan. 25, 1994 and assigned to apredecessor company of the assignee in the present application,discloses a reflector lamp of the PAR 16 dimension having a bipartiteneck. The mounting member, a plate with resilient tags which hold theseal with clamping force, is enclosed between the two parts of the neck.Such a lamp comprises a ceramic extender assembled on and glued to thereflector.

There is a need in the art for a PAR 38 lamp and lamp reflector unitthat comprises a halogen lamp of suitable power greater than 68 W, forexample 100 Watts coated with an infrared film to reflect the infraredenergy produced by the halogen lamp back to the filament, making it moreefficient; and/or that meets and preferably exceeds the minimum EPACTefficacy standards; and/or that exhibits a median life of at least about3000 hours, while giving light output greater than 90% from the originalvalue at about 1750 hours; and/or that exhibits all of the foregoingcharacteristics or combinations thereof.

An object of the invention is to provide a new PAR 38 lamp and lampreflector unit that comprises a halogen lamp of suitable power greaterthan 68 W, for example 100 Watts coated with an infrared film to reflectthe infrared energy produced by the halogen lamp back to the filament,making it more efficient; and/or that meets and preferably exceeds theminimum EPACT efficacy standards; and/or that exhibits a median life ofat least about 3000 hours, while giving light output greater than 90%from the original value at about 1750 hours; and/or that exhibits all ofthe foregoing characteristics or combinations thereof.

These and other objects of the invention will be apparent from adescription of the invention which follows.

The objects of the invention may be accomplished through the provisionof a PAR-38 lamp and lamp/reflector unit having the characteristicsdescribed above which comprises a reflector body (1) including areflector portion (2) having a concave reflecting surface (3) with anoptical axis (4) and, integral therewith, a hollow neck-shaped portion(5) about the optical axis (4), an electric lamp (10) comprising:

(a) a light-transmitting lamp vessel (11) said lamp vessel comprising aquartz-glass wall (12) which encloses a cavity (13) of a predetermined,in general, spherical or elliptical shape with a geometric center (14),

said wall (12) being at least partly provided with aninfrared-reflecting and visible light-transmitting coating (15), and

said cavity (13) accommodating a substantially linear electric lightsource 16 ),

(b) a metal foil (17, 18) which is entirely embedded in the wall (12)and connected to the electric light source (16),

(c) a first end portion (21) and a second end portion (22) which arearranged so as to be opposite to each other and which both comprise aseal,

(d) a respective current conductor (23; 24) connected to the embeddedmetal foil (17; 18 ) which issues from the lamp vessel (11) to theexterior, and is connected to metal foil through the seals,

(e) a metal positioning member (40) in the neck which holds the lampvessel and through which the lamp seal is passed,

(f) and a ceramic insert (42) beneath the mounting ring and throughwhich the seal of the first end portion is passed, wherein, the electriclamp (10) is arranged in the reflector body (1) in such a manner thatthe first end portion (21) is at least partly situated in theneck-shaped portion (5), the cavity (13) is situated within thereflecting portion (2), the electric light source (16) is predominantlysituated on the optical axis (4), and the ceramic insert is effective todissipate heat from the first end portion (21) during operation of thelamp.

U.S. Pat. No. 6,404,112B1, issued Jun. 11, 2002, titled “ElectricLamp/Reflector Unit” and assigned to the same assignee as in thisapplication, relates to a way to adapt the dimensions of a double-endedhalogen lamp and a reflector body so as to attain a satisfactorytemperature balance. These principles may be employed in this inventionas well and the disclosure of said patent is incorporated herein byreference. When embodied in the present invention, as described in saidpatent, the connection point (28) where the first end portion currentconductor (23) is connected to the metal foil (17) of the first endportion (21) may be a distance d_(c) ^(I) from the geometric center(14), the first end portion (21) will have a length l_(ep) ^(I) measuredfrom the geometric center (14), the connection point (27) where thesecond end portion current conductor (24) is connected to the metal foil(18) of the second end portion (22) will be a distance d_(c) ^(II) fromthe geometric center (14), the second end portion (22) will have alength l_(ep) ^(II) measured from the geometric center (14), and theratios of the distances d_(c) ^(I); d_(c) ^(II) to the respectivelengths l_(ep) ^(I); l_(ep) ^(II) is d_(c) ^(I)/l_(ep) ^(I)>0.75 andd_(c) ^(II); l_(ep) ^(II)>0.75.

In accordance with the invention, an improvement in PAR-38 lamps, it hasbeen found that the EPACT standards, the lamp efficiency and a long lamplife may be attained while lowering the press temperature to a safeoperating temperature by practicing the invention parameters abovedescribed.

In preferred embodiments of the invention, one of the end portions ofthe electric lamp is arranged at least partly in the neck portion of thereflector body, it is achieved, viewed along the optical axis, to reducethe relative height of the electric lamp, if desired, with respect tothe reflector body, which has a favorable influence on the ratio of thedimensions of the double-ended electric lamp with respect to thedimension of the reflector body of the known electric lamp/reflectorunit. In the known electric lamp/reflector unit, a double-ended halogenlamp is bodily arranged in the reflector portion of the reflector bodyby means of so-called mounting legs. By securing, in accordance with theinvention, the first end portion of the electric lamp in the neckportion of the reflector body, a sturdy and reliable connection of theelectric lamp with the reflector body is achieved. In addition, thepositioning of the electric light source on the optical axis of thereflector portion is improved thereby, the electric light sourcepreferably being positioned such that the geometric center of theelectric lamp is situated in the focus of the concave reflectingsurface. The improved positionability results in a higher light outputand a better light distribution of the electric lamp/reflector unit.

The inventors have recognized that in the known electric lamp/reflectorunit, the so-called pinch temperature of the electric lamp increasesduring operation which adversely affects, in particular, the servicelife of the electric lamp. The temperature of the pinch of a lamp ismeasured at the location of the connection point (generally formed by awelded joint) of the (external) current conductor and the metal foilembedded in the wall of the electric lamp. In general, a high pinchtemperature enhances corrosion of the metal foil and/or the externalcurrent conductor. Corrosion leads to failure of the lamp as a result ofthe current supply being interrupted. Other causes of failure include,for example, leakage of the lamp vessel or non-passive failure of thelamp. In the electric lamp in accordance with the invention, a ceramicinsert inside of a electric lamp/reflector unit is effective to lowerthe pinch temperature and avoid thermal shock of the halogen burner. Thehalogen burner is placed through the ceramic insert and fit into thereflector wherein the ceramic insert acts as a heat sink taking the heatoff the press. The ceramic insert fits tight onto the inside part of theglass reflector and has an orifice in the center which the halogenburner passes through. This allows the heat to be conducted off theburner and out of the lamp more effectively and a reduction of the pinchtemperature is obtained.

The safety of the electric lamp/reflector unit is enhanced if theemission window of the reflector body is closed by means of a lens (31).In this manner, it can be precluded that inflammable objects come intocontact with hot parts of the lamp. In addition, such a lens can limitthe risks as a result of a non-passive failure of the lamp vessel bycontaining within the outer envelope the energy released by thenon-passive failure. The lens may be fixed to the reflector body bymeans of an adhesive 43, for example silicone paste. Alternatively, thelens can be secured mechanically, using, for example, a metal ring whichis rolled over the reflector body. A clamping ring or a number of clampsmay alternatively be used. The lens may be flat or curved.

In a favorable modification, the reflecting portion has a substantiallycylindrical end portion near the lens. By virtue thereof, the volumewithin the reflecting portion can be larger so as to obtain a loweroverall temperature, if so desired, without the increase in volumeleading to an increase in diameter of the unit. It is alternativelypossible to provide the reflector body at the outside with a profiled,for example rippled, surface. As a result, the surface area isincreased, enabling a greater heat emission.

The electric lamp may be an incandescent body, for example in ahalogen-containing inert gas, or an electrode-pair in an ionizable gas.Particularly if the cavity of the lamp vessel is in the shape of anellipse provided with an infrared-reflecting and visiblelight-transmitting coating, and if a spiral-shaped linear incandescentbody is arranged in the cavity, the heat in the form of infrared lightgenerated by the incandescent body is very effectively reflected back tothe incandescent body, as a result of which the current demanded fromthe power source is reduced, so the lamp becomes more efficient.

The ceraminc insert may be formed of materials known in the art, forexample, it may be made of steatite, aluminum oxide, aluminum nitride,or the like. Particularly preferred for use herein is a materialavailable commercially as L3 Steatite which comprises SiO₂—MgO—BaO.

A particularly favorable embodiment of the electric lamp/reflector unitin accordance with the invention is characterized in that an internalcurrent conductor which connects the electric light source with themetal foil is bent such that the electric light source is substantiallysituated on the optical axis. The better the electric light source iscentered with respect to the spherical or elliptic shape of the cavity,the more effective the action of the infrared-reflecting coating and thehigher the efficiency of the electric lamp is. In addition, the betterthe electric light source is centered with respect to the geometriccenter, which is preferably situated on the optical axis of thereflector body, the better the light distribution is as a result of thereflection from the concave reflecting surface of the reflector body.

In order to further reduce the temperature of the end portions, said endportions may be sandblasted during the manufacture of the electric lamp.This has the advantage that the end portions are not covered with aninfrared-reflecting coating, which leads to a reduction of thetemperature of the end portions and hence of the pinch temperature. Anadditional advantage of sandblasting resides in that the surface of theend portions is roughened, so that a larger heat-radiating surface isobtained and hence overall internal light reflection in the end portionsas a result of the coating is reduced.

In a preferred embodiment of the electric lamp/reflector unit inaccordance with the invention, the metal foil and the first and thesecond current conductor may be at least partly provided with aprotective coating at the location of the connection point. Thisprotective coating reduces the risk of corrosion of the metal foil andthe current conductor at the location of the connection point. As aresult of said corrosion protection, an acceptable service life of theelectric lamp in the electric lamp/reflector unit may also be extendedwhile the risk of explosion of the lamp is negligible. Preferably, theprotective coating contains chromium. It has been found that chromiumcan be effectively used as a protective coating on electric conductorsof molybdenum and tungsten in quartz glass, and forms low-meltingproducts with these materials. A chromium protective layer having alayer thickness in the range from 0.5 to 2 .mu.m is particularlyfavorable. The layer thickness of the coating is a parameter which,among other things, determines the degree of corrosion protection.

In a particularly favorable embodiment, the current conductor is ledfrom the second end portion via an electroconductive connection to theneck-shaped portion of the reflector body. Preferably, the connection isat least partly made from nickel. Nickel is a stable material having agood coefficient of heat conduction and it can also be used as a contactmember of the electric lamp/reflector unit. A material which can bealternatively used for the manufacture of said connection is stainlesssteel.

These and other aspects of the invention will be apparent from andelucidated with reference to the embodiments described hereinafter.

The invention will be better understood with reference to the details ofspecific embodiments that follow.

FIG. 1 is a cross-sectional view of an electric lamp/reflector unit inaccordance with the invention;

FIG. 2 is a view of a ceramic insert of the invention; and

FIG. 3 is a perspective of the halogen burner with connectors, metalpositioning ring, ceramic insert, and reflector body of the invention(unassembled).

The Figures are purely diagrammatic and not drawn to scale. Particularlyfor clarity some dimensions are exaggerated strongly. In the Figures,like reference numerals refer to like parts whenever possible.

FIG. 1 shows an electric lamp/reflector unit in accordance with theinvention in cross-section. As illustrated, the electric lamp/reflectorunit 50 comprises a shaped reflector body 1 having a reflector portion 2with a concave reflecting surface 3 and an optical axis 4. A hollow,neck-shaped portion 5 situated around the optical axis 4 is integralwith the reflector portion 2. In the example shown in FIG. 1, theemission window of the reflector body 1 is closed by means of a curvedlens 31. In an alternative embodiment, said lens 31 is flat. Theembodiment of the electric lamp/reflector unit shown in FIG. 1 is thereflector body 1 of the PAR 38 type.

The electric lamp/reflector unit further comprises an electric lamp 10including a gastight light-transmitting lamp vessel 11 having a quartzglass wall 12 enclosing a cavity 13 of a predetermined, generally,spherical or elliptic shape with a geometric center 14. In the exampleshown in FIG. 1, the shape of the cavity 13 is substantially elliptical.The cavity 13 of the lamp vessel 11 accommodates a substantially linearelectric light source 16, for example an incandescent body in the formof a spirally wound tungsten wire. At the location where the wall 12 ofthe lamp vessel 11 is elliptical in shape, the wall 12 of the lampvessel 11 is provided with an infrared-reflecting and visiblelight-transmitting coating 15. The infrared radiation generated by theincandescent body is reflected back to the incandescent body by thiscoating 15, causing the efficiency of the electric lamp 10 to beincreased substantially. The visible light is passed by the coating 15.

The infrared-reflecting and visible light-transmitting coatings 15 areknown per se. Such (>40 layers), the thicknesses of the individualcoatings generally comprise a multilayer interference filter opticallayers being calculated by means of computer programs known to thoseskilled in the art. Such optical interference films are generallyapplied by means of coating techniques which are known per se, such asvapor deposition, dip coating, (reactive) sputtering and chemical vapordeposition.

In FIG. 1, the geometric center 14 of the electric lamp/reflector unitis situated at the intersection of the optical axis 4 and a further axis4′; 4″ at right angles to the optical axis 4, in the center of the lampvessel 11. In the wall 12 of the electric lamp 10, metal foils (17, 18)may be embedded on both sides. These metal foils are connected to theelectric light source 16. The electric lamp 10 further comprises a firstend portion 21 and a second end portion 22 which are both provided witha seal. The second end portion 22 is arranged so as to be opposite tothe first end portion 21. An electric lamp 10 comprising a combinationof two end portions 21; 22 between which there is a cavity is commonlyreferred to as a double-ended electric lamp, in the example shown inFIGS. 1 and 3, a so-called double-ended halogen lamp. Through the endportions 21; 22, current conductors 23; 24 which are connected to theembedded metal foil issue from the lamp vessel 11 to the exterior.

The electric lamp 10 is arranged in the reflector body 1, the first endportion 21 being situated at least partly in the neck-shaped portion 5,the cavity 13 being situated within the reflecting portion 2, and theelectric light source 16 being situated substantially on the opticalaxis 4.

FIG. 1 further shows that the current conductor 24 projects from thesecond end portion 22 and is guided via an electroconductive connection34, to the neck-shaped portion 5 of the reflector body 1. A particularlyfavorable connection 34 is made from nickel. The current conductor 23 iscorrespondingly connected to an electroconductive connection 33. Theseparts are passed through the metal positioning ring 40 and through theceramic insert 42 with the connectors 34 and 33 passing through holes 44of the ceramic insert. Both connections 33; 34 issue from the ceramicinsert to the exterior to eyelets 28 which complete the connection tofuse wire 29 and nickel wire 27 which are welded, soldered or otherwiseattached to the skirted base 30.

Two types of 100 watt/120 volt double-ended halogen lamp vessels wereevaluated for the manufacturing of a PAR 38 electric lamp/reflector unitof this invention. Lot A lamp vessels were manufactured with filling gaswith 5.5 Bars of pressure, and Lot B were manufactured with filling gaswith 6.5 Bars of pressure. A sample of 20 capsules of each lot wasassembled into PAR 38 lamps and they were lifetime tested. The resultsare reported in Table 1.

TABLE #1 Lifetime lamps manufactured without ceramic insert. TEST ACTUALLAMP NUMBER FAILURE FAILURE NUMBER LIFETIME SAMPLE OF FAILURES RATE MODE2ET31 1705 hours 20 20 5% at 837 hours. 1× split pinch. Lamps madewithout 35% at 1059 hours. 3× Split pinch, blackening, broken coil.ceramic insert 3× Split pinch, broken coil. Capsules from lot A. 5% at1195 hours. 2× Split pinch, broken coil. 1× Split pinch, broken coil,blackening 65% at 1206 hours. 1× Split pinch, 1× split pinch,blackening. 1× Split pinch. 90% at 1463 hours 3× Split pinch,blackening, broken coil. 1× Split pinch, broken coil. 95% at 1569 hours1× Split pinch, blackening, broken coil. 100% at 1705 hours 1× Splitpinch, broken coil. 2ET25 1596 hours 20 20 30% at 671 hours. 2× Splitpinch, broken coil. Lamps made without 4× Split pinch, broken coil,blackening. ceramic insert 55% at 839 hours. 1× Split pinch, brokencoil. Capsules from lot B. 4× Split pinch, broken coil, blackening. 60%at 999 hours. 1× Split pinch, broken coil, blackening. 80% at 1181hours. 4× Split pinch, broken coil. 90% at 1343 hours. 1× Split pinch 1×Split pinch, blackening. 95% at 1443 hours. 1× Split pinch, blackening,broken coil. 100% at 1596 hours. 1× Split pinch blackening, broken coil.

In this test the results in lifetime were very poor having a median lifearound 900 to 1300 hours. In addition, it was also observed that thecommon failure mode was split pinch on the capsules. Moreover, beforethe pinch of the lamp vessel or capsule split, the high workingtemperature caused the coating applied to the body of the capsule todegrade. This degradation manifested itself by turning the capsuleblack, thus reducing the light output.

A thermocouple was attached in the pinch area of the burner and it wasassembled into a lamp. This lamp was lighted in fixtures during one hourand the temperature was registered. This procedure was performed on fivelamps to choose the maximum temperature of the five lamps.

Because of the high temperature found in this test, five lamps wereassembled with a ceramic insert to investigate if this ceramic couldreduce the pinch temperature. The results are reported in Table 2.

TABLE #2 Capsule pinch temperature. CAPSULE PAR 38 LAMP TEMPERATUREDESCRIPTION Ceramic No ceramic DIFFERENCE 100 W/120 V 359° C. 445° C.86° C. 100 W/130 V 342° C. 407° C. 65° C. *92 W/120 V 318° C. 378° C.60° C. Note: *Lamps with 100 watts/130 volts capsule tested @ 120 volts.

From these results it was observed that the ceramic insert reduced thecapsule working temperature.

Another sample of 20 capsules of each lot (A and B) was assembled intoPAR 38 lamps for lifetime evaluation. This time the ceramic insert wasadded to the lamp assembly. The results are reported in Table 3.

TABLE #3 Lifetime performed to lamps manufactured with ceramic insert.TEST ACTUAL LAMP NUMBER FAILURE FAILURE NUMBER LIFETIME SAMPLE OFFAILURES RATE MODE 2ET42 >1600 hours 20 0 0 No failures have occurredyet and the Lamps made with test is on going. ceramic insert Capsulesfrom lot A. 2ET35 >2700 hours 20 0 0 No failures have occurred yet andthe Lamps made with test is on going. ceramic insert Capsules from lotB.

The above lifetime tests were extended. No failures have occurred after3000 hours and the tests are still ongoing.

The lamp vessel 11 of the double-ended halogen lamps in accordance withthe invention preferably has an elliptical cavity 13. The outer surfaceof the cavity 13 is provided with an infrared-reflecting and visiblelight-transmitting coating 14. The coating 14 preferably comprises a47-layer Nb₂O₅/SiO₂ infrared-reflecting interference filter which isprovided by means of reactive sputtering.

It will be obvious that, within the scope of the invention, manyvariations are possible to those skilled in the art. For example, theinvention is not limited to an electric lamp/reflector unit comprisingan electric lamp including an incandescent body; the electric lamp mayalternatively comprise an electrode pair in an ionisable gas. Inaddition, the infrared-reflecting and visible light-transmitting coatingprovided on the electric lamp may be omitted.

The scope of protection of the invention is not limited to theabove-described examples. The invention is embodied in each novelcharacteristic and each combination of characteristics. Referencenumerals in the claims do not limit the scope of protection thereof. Theuse of the term “comprising” does not exclude the presence of elementsother than those mentioned in the claims. The use of the word “a” or“an” in front of an element does not exclude the presence of a pluralityof such elements.

1. An electric lamp/reflector unit, capable of operating at a powergreater than 68 W, comprising: a reflector body including a reflectorportion having a concave reflecting surface with an optical axis and,integral therewith, a hollow neck-shaped portion about the optical axis,an electric lamp comprising: (a) a light-transmitting lamp vessel, saidlamp vessel comprising a quartz-glass wall which encloses a cavity of apredetermined, in general, spherical or elliptical shape with ageometric center, said wall being at least partly provided with aninfrared-reflecting and visible light-transmitting coating, and saidcavity accommodating a substantially linear electric light source, (b)first and second metal foils which are entirely embedded in the wall andconnected to the electric light source, (c) a first end portion and asecond end portion which are arranged so as to be opposite to each otherand which both comprise a seal, wherein said second end portion is abovethe neck-shaped portion and is within the reflector portion, (d) firstand second current conductors respectively connected to the embeddedfirst and second metal foils through respective seals of the first andsecond end portions, wherein said current conductors issues from thelamp vessel to the exterior, (e) an electroconductive connector that iscoupled to the second current conductor issuing from the second endportion, (f) a metal positioning member in the neck-shaped portion whichholds the lamp vessel and through which the seal of the first endportion is passed, and (g) a ceramic insert beneath the metalpositioning member and through which the seal of the first end portionand the electroconductive connector are passed, wherein the ceramicinsert is dimensioned such that a lateral thickness of the ceramicinsert between the electroconductive connector and a closest outer wallof the ceramic insert is greater than a distance between theelectroconductive connecter and a portion of the optical axis on whichthe first end portion is situated, and the electric lamp is arranged inthe reflector body in such a manner that the first end portion is atleast partly situated in the neck-shaped portion, the cavity is situatedwithin the reflecting portion, the electric light source ispredominantly situated on the optical axis, and the ceramic insert iseffective to dissipate heat from the first end portion during operationof the lamp.
 2. An electric lamp/reflector unit as claimed in claim 1,wherein the electric lamp meets at least the minimum EPACT efficacystandards.
 3. An electric lamp/reflector unit as claimed in claim 1,wherein the connection point where the first current conductor isconnected to the first metal foil in the first end portion is a distanced_(c) ^(I) from the geometric center, the first end portion has a lengthl_(ep) ^(I) measured from the geometric center, the connection pointwhere the second current conductor is connected to the second metal foilin the second end portion is a distance d_(c) ^(II) from the geometriccenter, the second end portion has a length l_(ep) ^(II) measured fromthe geometric center, and the ratios of the distances d_(c) ^(I); d_(c)^(II) to the respective lengths l_(ep) ^(I) ; l_(ep) ^(II) is d_(c)^(I)/l_(ep) ^(I)>0.75 and d_(c) ^(II)/l_(ep) ^(II)>0.75.
 4. An electriclamp/reflector unit as claimed in claim 1, wherein the ceramic insertfits tight onto the inside part of the glass reflector and has anorifice in the center which the lamp vessel passes through.
 5. Anelectric lamp/reflector unit as claimed in claim 1, wherein thereflector body is closed by means of a lens.
 6. An electriclamp/reflector unit as claimed in claim 5, wherein the cavity of thelamp vessel is in the shape of an ellipse and is provided with aninfrared-reflecting and visible light-transmitting coating.
 7. Anelectric lamp/reflector unit as claimed in claim 6, wherein aspiral-shaped linear incandescent body is arranged in the cavity and theheat in the form of infrared light generated by the incandescent body isreflected back to the incandescent body.
 8. An electric lamp/reflectorunit as claimed in claim 1, wherein the electroconductive connector is afirst electroconductive connector, the second current conductor isguided via the first electroconductive connector to the neck-shapedportion of the reflector body and the first current conductor iscorrespondingly connected to a second electroconductive connector.
 9. Anelectric lamp/reflector unit as claimed in claim 8, wherein theelectroconductive connectors are at least partly made from a nickel orstainless steel member.
 10. An electric lamp/reflector unit as claimedin claim 1, wherein the coating comprises a multilayer interferencefilter.
 11. An electric lamp/reflector unit as claimed in claim 10,wherein said coating is a layered Nb₂O₅/SiO₂ infrared-reflectinginterference filter.
 12. An electric lamp/reflector unit as claimed inclaim 8, wherein: the lamp vessel with the connectors pass through themetal positioning member and through the ceramic insert, with theconnectors passing through holes of the ceramic inset
 13. An electriclamp/reflector unit as claimed in claim 12, wherein said connectorsissue from the ceramic insert to the exterior to eyelets.
 14. Anelectric lamp/reflector unit as claimed in claim 13, wherein saideyelets complete a connection to fuse wire and nickel wire which areattached to a skirted base.
 15. An electric lamp/reflector unit asclaimed in claim 1, wherein the electric lamp/reflector unit is a PAR 38lamp/reflector unit, wherein said electric lamp is a halogen lamp ofpower greater than 68 W coated with an infrared film to reflect theinfrared energy produced by the halogen lamp back to a filament toimprove efficiency, wherein said PAR 38 lamp/reflector unit meetsminimum EPACT efficacy standards and exhibits a median life of at leastabout 3000 hours.
 16. An electric lamp/reflector unit, capable ofoperating at a power greater than 68 W, comprising: a reflector bodyincluding a reflector portion having a concave reflecting surface withan optical axis and, integral therewith, a hollow neck-shaped portionabout the optical axis, an electric lamp comprising: (a) alight-transmitting lamp vessel, said lamp vessel comprising aquartz-glass wall which encloses a cavity of a predetermined, ingeneral, spherical or elliptical shape with a geometric center, saidwall being at least partly provided with an infrared-reflecting andvisible light-transmitting coating, and said cavity accommodating asubstantially linear electric light source, (b) a first and second metalfoils which are entirely embedded in the wall and connected to theelectric light source, (c) a first end portion and a second end portionwhich are arranged so as to be opposite to each other and which bothcomprise a seal, wherein said second end portion is above theneck-shaped portion and is within the reflector portion, (d) first andsecond current conductors respectively connected to the embedded firstand second metal foils through respective seals of the first and secondend portions, wherein said current conductors issue from the lamp vesselto the exterior, (e) a first electroconductive connector that is coupledto the second current conductor issuing from the second end portion, (f)a metal positioning member in the neck-shaped portion which holds thelamp vessel and through which the seal of the first end portion ispassed, (g) a ceramic insert beneath the metal positioning member andthrough which the seal of the first end portion and the firstelectroconductive connector are passed, wherein, the ceramic insert isdimensioned such that a lateral thickness of the ceramic insert betweenthe first electroconductive connector and a closest outer wall of theceramic insert is greater than a distance between the firstelectroconductive connecter and a portion of the optical axis on whichthe first end portion is situated, the electric lamp is arranged in thereflector body in such a manner that the first end portion is at leastpartly situated in the neck-shaped portion, the cavity is situatedwithin the reflecting portion, the electric light source ispredominantly situated on the optical axis, and the ceramic insert iseffective to dissipate heat from the first end portion during operationof the lamp, and the second current conductor is guided via the firstelectroconductive connector to the neck-shaped portion of the reflectorbody and the first current conductor is correspondingly connected to asecond electroconductive connector, the lamp vessel with the connectorspass through the metal positioning member and through the ceramicinsert, with the connectors passing through holes of the ceramic insert,said connectors issue from the ceramic insert to the exterior toeyelets, wherein said eyelets complete a connection to a fuse wire andnickel wire which are attached to a skirted base.
 17. An electriclamp/reflector unit as claimed in claim 1, wherein the electric lampexhibits a median life of at least about 3000 hours.